It is well known to manufacture gears, such as bevel and hypoid gears, with stick-type cutting blades made from, for example, high speed steel or carbide materials. It is further known that to form, or to restore, the desired surfaces and edges on stick-type cutting blades, grinding operations must be performed on the cutting blades. Examples of such cutting blades can be found in U.S. Pat. No. 4,575,285 to Blakesley; U.S. Pat. No. 5,890,846 to Clark et al. or U.S. Pat. No. 6,120,217 to Stadifeld et al. Cutting blades of this type have cutting and clearance profile surfaces as well as a top surface that are ground during sharpening. Other cutting blades are known where in addition to grinding the cutting, clearance and top surfaces as described above, the front face of the cutting blade is also ground when sharpening.
Cutting blade grinding machines (which also may be referred to as “sharpening” machines) for grinding cutting blades include some type of clamping mechanism for holding one or more cutting blades in position during grinding. Such clamping mechanisms generally hold a cutting blade in an angled orientation with respect to the axis of the clamping mechanism, or, in a “zero angle” orientation wherein the cutting blade is positioned coincident or parallel with the axis of the clamping mechanism.
In grinding a cutting blade in an angled orientation, the area of contact between the cutting blade and the grinding wheel generally stays in about the same location on the grinding wheel because the clamping mechanism remains in the same position (or 180 degrees relative to that position) during grinding. Such positioning keeps the top surface of the cutting blade positioned relative to the grinding wheel at about the same area of the grinding wheel during the grinding process. Thus, when introducing coolant during the grinding process, one or more coolant nozzles can be positioned and allowed to remain in the same position as the cutting blade is ground. However, with clamping mechanisms of the angled type, the orientation of a cutting blade is dependent upon the top angle of the cutting blade as well as the mounting angle of the cutting blade in its intended cutter head. Therefore, grinding cutting blades with different top or mounting angles requires different clamping mechanisms or positioning inserts in the clamping mechanism to accommodate the different cutting blades.
With clamping mechanisms of the “zero angle” type, the orientation of each blade remains parallel with the axis of the clamping mechanism during grinding. However, if it becomes necessary to rotate the clamping mechanism to different positions during grinding in order to properly grind the different surfaces on the cutting blade, the location of the contact area on the grinding wheel change may change. Thus, it becomes necessary to either reorient the positions of coolant nozzles or provide a plurality of coolant nozzles positioned to account for the different locations of the grinding area on the grinding wheel. Usually, coolant lines extend from a coolant header mounted stationary on the grinding wheel side of the machine. Having many coolant lines, and hence many coolant nozzles, can result on interference situations with machine components as well as requiring a greater volume of coolant as the number of lines increases.